Method of extracting the content of vegetal cells through mechanical means



United States Patent fifice 2,817,591 Patented Dec. 24, 1957 METHOD OF EXTRACTING THE CONTENT OF VEGETAL CELLS THROUGH MECHANICAL MEANS Lucien Marius Romagnan, Nice, France No Drawing. Application May 6, 1954 Serial No. 428,111

Claims priority, application France December 14, 1953 3 Claims. (Cl. 99-140) This invention relates generally to the processing of vegetal cells and more particularly to a method utilising mechanical means for the partial or total extraction of aromatic oils, essential oils and fats from vegetal cells.

Methods are already known wherein supersonic radiations acting in a gaseous or liquid medium are used for carrying out the extraction.

The method according to this invention is advantageous over prior art methods in that it is much simpler and requires no intricate or costly apparatus.

The method according to this invention is remarkable notably in that the grains, seeds, pods, shells, beans, nibs or other natural supports of the aforesaid vegetal cells are placed in a desired medium, for example a medium in which the said extracts are not directly soluble, and the mixture is subjected to a vigorous mechanical stirring, triturating and grinding action.

The term natural support is intended to mean any vegetal substances such as grains (coffee), roots (chicory), beans (vanilla), nibs (cocoa, tonka), citrus friuts, barks, etc.

More particularly, the medium may consist of liquids which are or not specific solvents of the treated substance, and specially selected to permit, after agitation, a rapid fractionation for isolating the extract, or, more simply, this medium may be aqueous.

The operation may be carried out either in the cold or in the hot, under reduced pressure, room pressure or subatmospheric pressure.

The mechanical agitation may be effected for example by a mechanical agitator of the type comprising rotary blades driven at very high speed (of the order of 10,000 to 14,000 R. P. M., according to the character of the substance treated), such as the apparatus known in the trade under the generic name of mixers, and its purpose is to impress a very fast movement to each particle located in the container of the apparatus while simultaneously grinding this particle to an instantaneous high degree of division.

Then the product is extracted either by diffusion, or by bursting the cells, or simultaneously through both actions, the cellulose walls or cell diaphragms being cleaned from any residual adherent products at the end of the operation.

The duration of the process may be very short, of the order of a few minutes only, but at any rate it may be extended until the substance to be treated is completely exhausted.

At the end of the operation a mass, sludge or liquid is obtained which contains the cell residues soaked in their extract. Then this mixture may be subjected to a fractionating process such as filtration, decantation, centrifugation or evaporation in order to separate the liquids containing the desired substances from the cell fragments and to increase their concentration.

According to the method of fractionation resorted to, the extracts may be collected in liquid, semi-liquid or dry form.

The resulting extracts are remarkable notably in that they are highly soluble in those liquids which, normally, are inadequate for separating extracts from their natural supports, the non-soluble portion remaining in suspension in a finely divided condition.

Therefore, these extracts may appear in the form of an aqueous solution possibly accompanied by a very fine dispersion.

The description will be given hereafter, by way of example, of a specific form of embodiment of the method of the invention as applied to the treatment of vanilla beans.

The vanilla beans are deposited in an apparatus constituted by a container, of the socalled mixer type, crosshammer mill type, etc., in which blades or like metal members are rotatably driven at very high speed. The beans are introduced into this apparatus, either in their original condition or coarsely ground, and subsequently a liquid, for instance water, is used to cover the solid content and constitute the medium in which the required stirring action may take place.

After a relatively short stirring time (2 to 4 minutes, the velocity of the mechanical agitator being of 10,000 to 14,000 R. P. M.) the resulting sludge is filtered and a liquid vanilla extract is obtained which contains all the aromatic elements of the original bean and are ready for use as such in the various fields concerned (ice-creams, pastry-making, etc.).

By concentrating the liqiud, increasingly heavier extracts are obtained, that is, extracts containing an increasing proportion of aromatic principals.

It is obvious that the liquids thus obtained may have the desired concentration and provide successively, by evaporation: pastry extracts, oleoresins, and, by complete drying, soluble dry extracts, which, when dissolved in water, milk, etc., will reconstitute the original. aroma and taste of the vanilla bean.

Now a practical example will be given by way of illustration of one manner in which the method of the invention may be carried out. 50 g. of Bourbon vanilla beans are placed in an amount of water seven times greater, i. e. 350 g., and the whole is subjected during two minutes to the triturating and grinding action of a mixer driven at about 12,000 R. P. M.; then the mixture in sludge condition is filtered by centrifugation and an aqueous extract weighing 334 g. and of concentration 5, that is, containing 16.70 g. of dry bean extract products, are obtained.

Thus, the primary yield of extraction is 33.4%.

Through a simple washing operation the residue still present in the sludge may be recovered. This primary extraction residual sludge, weighing 67 g., when washed in 350 g. of water, yields 340 g. of a liquid having a concentration of 1.4, i. e. having a dry extract content of 4.76 g.

The final yield of the primary extraction is therefore 21.46 g. of dry products, corresponding to a total percentage of 40%.

The thus washed sludge, subjected to another extraction, did not yield any useful product and seemed to consist only of cellulose residues.

The 334 g. of extract of concentration 5 resulting from the first operation are re-cycled to effect another extraction on 50 g. of fresh vanilla. After a two-minute treatment, the filtered, centrifugated product yields 295 g. of extract having a concentration of 9.8. Thus, this extract contains 28.91 g. of dry extract which, considering the increase due to the incorporation of 50 g. of fresh vanilla, represents a percentage of 24.4%. The new sludge weighing 86 g. is washed in 350 g. of water and yields 365 g. of an extract of concentration 2.2 containing 8.03 g. of dry extract. As a whole, this second operation yields 20.24 g. of dry extract, the general percentage of extraction being 40%.

By repeating this sludge-enriching operation, extracts of progressively increasing concentration (12.8, 15.6, etc.) are obtained. Apparently, the rate of extraction calculated on the total dry extract (extraction washing) shows a constant of about 40%.

Of course, the rate of extraction changes according to the qualities of vanilla employed. Apparently, it is specific of each of them.

The foregoing proves that:

(i) A single operation (one passage through the apparatus) will extract nearly 100% of the vanilla contained in the bean;

(ii) By adding fresh beans to the previously treated sludge, predetermined degrees of concentration may be obtained;

(iii) A simple washing operation will permit of in corporating in the initial extraction circuit not fresh Water but sludges of a concentration of 2 to 4% and even more, whereby, when it is desired to obtain highly concentrated final sludges, the number of operations may be reduced;

(iv) Since it is an easy matter to determine the rate of extraction of a given vanilla quality, it is possible to determine beforehand the composition of an extract by simply proportioning the Weight of vanilla to the Weight of the liquid medium.

it is also within the scope of this invention to provide any products obtained by carrying out the method disclosed hereinabove, these products being remarkable notably in that they are available in either liquid or dry form and have a very high degree of solubility in liquids which are normally inadequate for separating extracts from their natural supports, the non-soluble portion remaining in suspension in a finely divided condition.

Of course, the invention is not restricted to the form of embodiment and proportions given hereinabove by way of example only, for many modifications may be brought thereto without departing from the spirit and scope of the invention.

What is claimed is:

1. A process for the extraction of aromatic oils, essential oils and fats contained in vegetal cells, comprising the steps of mixing vegetal cells with water in which the extracts from the cells are not soluble, subjecting the mixture to strong mechanical agitation in the form of high velocity grinding and cutting action, and fractionating the liquid medium resulting therefrom to obtain a solution having therein a very fine dispersion of the oils and fats from the vegetal cells.

2. A process for the extraction of aromatic oils, essential oils and fats contained in vegetal cells, comprising the steps of mixing vegetal cells with cold water in which extracts from the cells are not soluble, subjecting the cold mixture to strong mechanical agitation in the form of high velocity grinding and cutting action for a short period of'time and at subatmospheric pressure, and fractionating the liquid medium resulting therefrom to obtain a solution having therein a very fine dispersion of the oils and fats from the vegetal cells.

3. A process for the extraction of aromatic oils, essential oils and fats contained in vegetal cells, comprising the steps of mixing vegetal cells With cold Water in which extracts from the cells are not soluble, subjecting the cold mixture to strong mechanical agitation in the form of high velocity grinding and cutting action for a short period of time and at subatmospheric pressure, and fractionating the liquid medium resulting therefrom to obtain a solution having therein a very fine dispersion of the oils and fats from the vegetal cells, and repeating said steps on the residual material left after the fractionating of the liquid medium.

References Cited in the file of this patent UNITED STATES PATENTS 2,065,863 Madaus Dec. 29, 1936 2,358,947 Towt Sept. 26, 1944 2,511,115 Lazier June 13, 1950 2,601,635 Romagnan June 24, 1952 OTHER REFERENCES Vanilla Extract by Dean et al., The Journal of Industrial and Engineering Chemistry, July 1916, vol. 8,

No. 7, page 609. 

1. A PROCESS FOR THE EXTRACTING OF AROMATIC OILS, ESSENTIAL OILS AND FATS CONTAINED IN VEGETAL CELLS, COMPRISING THE STEPS OF MIXING VEGETAL CELLS WITH WATER IN WHICH THE EXTRACTS FROM THE CELLS ARE NOT SOLUBLE, SUBJECTING THE MIXTURE TO STRONG MECHANICAL AGITATION IN THE FORM OF HIGH VELOCITY GRINDING AND CUTTING ACTION, AND FRACTIONATING THE LIQUID MEDIUM RESULTING THREFROM TO OBTAINED A SOLUTION HAVING THEREIN A VERY FINE DISPERSION OF THE OILS AND FATS FROM THE VEGETAL CELLS. 